Darling Exchange – Sydney


ADDRESS:             Darling Exchange
YEAR:                     Jan 17 – Nov 19
AREA:                     6,604 sqm

The building of Darling Exchange is located at the south end of the Chinese Gardens, in Sydney’s CBD. These gardens offer an insight into Chinese heritage and Asian culture and link the popular Darling Harbour to the new residential and commercial development area known as The Exchange.

AR-MA collaborated with Lendlease, Kengo Kuma, and the sub-contractors to build a highly detailed 3D model that integrated manufacturing and construction knowledge from all parties.
The model was a continuous process that spanned from design through to fabrication and installation. It was used for design review, construction review, material procurement, sub-contractor pricing, and fabrication output. The team of 3 dedicated to this project undertook a large scope of work which consisted of resolving the system of the timber facade, developing the glass balustrade, designing the stainless steel stairs, and creating a system which coordinates all these elements with the slab edge.

During the design stage, I used the Virtual Construction process to maintain and enhance the architect’s design intent. I developed this process by carefully understanding what the architect wanted to achieve and marrying this with available fabrication, assembly and installation techniques through an integrated 3D model. This approach is also known as DfMA (Design for Manufacture and Assembly)

Furthermore, I created and deployed tools, workflows and processes such as the material optimisation that allowed me to reduce the wastage of timber on the façade by 24%.
In addition, Lendlease was able to fast-track the façade construction due to all parties being involved in the early stages to resolve the detailing of the façade system.


My first responsibility was to design a platform that was able to bring together the information from multiple systems into one place: the Formwork.
The 3D model of the Formwork was developed to save time on site as well as to maintain precision for the installation of the timber facade.
The Edge-form system was subdivided into modules, each module contains information from other systems such as the location of the facade connections, the location of the balustrade stanchions, the set-out of slab-edge and the location of the PTs (Post Tension).


The facade system that supports the timber strips consists of 4 bespoke elements: angles, post, outrigger and plate. These components are the result of previous analysis and specific engineering requirements.
To develop the design of the facade I have subdivided the process into three steps: the Posts optimisation, the Joints distribution and the Booms resolution.
The Posts optimisation is the process that allowed me to place each post on the slab edge and provide an initial catalog of post profiles.
To undertake this task, I developed an optimisation strategy using evolutionary algorithms and solver which can accommodate numerous parameters and assumptions.

The Post spacing tool follows these construction and feasibility rules:

  • avoiding the PT (Post tension) pockets
  • minimising the number of modules
  • minimising the wastage of the timber strips
  • using the available stock lengths of timber strips
  • control the stagger in the whole facade.

The outcomes of this first process have been used as input for the next steps.

The Joints distribution process helped to refine the lengths of the timber strips and added the type of joint that the architects required, such as the Butt joint and the Overlap.
By defining the location of the joints, it allowed me to control the aesthetic of the facade and provided information about the orientation of the connections to the posts.

The last step in the process was the Booms resolution and it involved solving the different conditions and clashes between booms and timber strips on the facade. For this task, I chose to create a Python script that was able to recognize every possible condition, modify the post following certain rules and output the final outline without clashes. This tool helped me to manage the 309 unique posts in the facade and to provide a highly detailed 3D model.


The final phase of the project involved translating the 3D data into fabrication outputs and instructions in order to coordinate the manufacture and installation of all components.
Subdividing the facade into assemblies in the earlier stages of the project enabled me to create a system where the data has driven the production stage and simplified the assembly of each module.
Every component in the facade has been issued with the cut file, a check drawing and set-out for the assembly.


ARCHITECT: Kengo Kuma Architect – Japan


Massimiliano Manno, Cnd